top.hmtools.Math

Class Calculator

java.lang.Object

top.hmtools.Math.Calculator

public class Calculator
extends Object

算数表达式求值 直接调用Calculator的类方法conversion() 传入算数表达式，将返回一个浮点值结果 如果计算过程错误，将返回一个NaN

Constructor Summary

Constructors

Constructor and Description
Calculator()

Method Summary

Modifier and Type	Method and Description
double	calculate(String expression) 按照给定的表达式计算
boolean	compare(char cur, char peek) 利用ASCII码-40做下标去算术符号优先级
static double	conversion(String expression)

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

Calculator

public Calculator()

Method Detail

conversion

public static double conversion(String expression)

calculate

public double calculate(String expression)

按照给定的表达式计算

Parameters:

expression - 要计算的表达式例如:5+12*(3+5)/7

Returns:

compare

public boolean compare(char cur,
                       char peek)

利用ASCII码-40做下标去算术符号优先级

Parameters:

cur -

peek -

Returns: